JPH01303682A - Flexible optical disk - Google Patents

Abstract

PURPOSE:To hold high positional accuracy required to an optical recording medium without losing flexibility by providing a hub constitution at the center part of a flexible optical disk. CONSTITUTION:A hub 3 is provided at a center part 2 of a flexible optical disk 1, that is, a part supported on recording/reproducing. The size and weight of the hub 3 part are not limited in particular when they are within a range fixed by the optical disk standard. Besides, the hub 3 part can be provided at any process when it is before recording and reproducing are practiced, and it can be formed at the same time when a pit column, a guiding channel and so on are formed. Thus, the flexible optical disk 1, of which high positional accuracy required to an optical recording medium is held, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention: (Industrial Field of Application) The present invention relates to the structure of a flexible optical disc.

(Prior Art) Recent optical recording systems that use laser light to record and reproduce information are capable of high-density recording, have a short readout time, and are also capable of recording and reproducing information. Since playback is performed without contact, the recording medium is attracting attention because of its excellent durability.

In conventional optical recording systems, information is recorded and reproduced by focusing laser light into a minute point on the recording layer of the optical recording medium. High positional accuracy of the relative positions of grooves, etc. is required. Ordinary optical recording media use glass plates, plastic plates, etc. with a thickness of 1 mm or more, and strive to ensure high flatness accuracy by taking advantage of their rigidity. It is impossible to correct it. However, by making the optical recording medium flexible,
Warps and waviness that occur during use can be corrected with a small amount of stress, and high planar accuracy can be easily ensured (for example, Japanese Patent Laid-Open No. 129981/1983).

(Problems to be Solved by the Invention) In the conventional flexible optical recording medium described above, when recording and reproducing information, the flexible optical recording medium is surrounded by a transparent plate that can transmit the laser beam for recording and reproducing. Since they are used in parallel, they have the disadvantage of having multiple components.

In this case, it is extremely difficult to set these multiple components together while maintaining the high positional accuracy required for an optical recording system.

Therefore, an object of the present invention is to provide a flexible optical disk that maintains the high positional accuracy required for optical recording media.

Structure of the Invention; (Means for Solving the Problems) As a result of intensive studies to solve the above-mentioned problems, an optical disc recording/reproducing device supports the central part of the optical disc to record/reproduce information. By providing a hub structure at the center of the flexible optical disk, that is, the part that is supported during recording and playback, we have achieved the high performance required for optical recording media without sacrificing its flexibility. We found that it is possible to maintain positional accuracy.

That is, the present invention relates to a flexible optical disc in which an optical recording layer is provided on one side of a flexible film.
The above objects of the present invention are achieved by providing a hub structure at the center of the flexible optical disk.

(Function) FIG. 1 is a plan view of the flexible optical disk 1 of the present invention, and FIG. 1(B) is a sectional view thereof. flexible optical disc 1
The central part 2 of the disc, that is, the thick part that is supported during recording and playback, is the hub 3, and there are no particular restrictions on the size and weight of the hub 3 as long as they are within the range stipulated by the optical disc standard. .

Next, this hub 3 portion may be provided at any step before recording/reproducing, and may be formed at the same time as forming pit rows, guide grooves, etc. Alternatively, the hub 3 may be bonded to the center portion 2 after forming the bit rows or guide grooves, etc. The material of the hub 3 may be any material as long as it satisfies the regulations regarding the weight of optical disks stipulated in the optical disk standard. The material may be suitable, such as metal or plastic.

(Example) This invention will be further explained below by giving specific examples.

An ultraviolet curable modified acrylate resin is sandwiched between a polyester film having a thickness of 100 μl and a nickel stamper having a concave-convex signal.
After pressing with a pressure of m', polyvarnish.

Approximately 200a using a high pressure mercury lamp through the chill film surface
After irradiating ultraviolet light with an amount of +J/cm2, the film was peeled off from the stamper, and the modified acrylate resin side was further irradiated with ultraviolet rays with an amount of about 80 On+J/cm2 using the above-mentioned ultraviolet light source. I got it. Next, 1,000 aluminum bases were formed on the uneven surface of this film, and a hole was made in the center.
The entire disc was cut out concentrically with the center hole to obtain a playback-only optical disc. Figure 2 (^), (I
t) The aluminum hub 4 shown in Figure 1 (8) is pasted together using an anaerobic adhesive from the side opposite to the uneven surface.
, (A flexible optical disk having the hub structure shown in [1) was obtained.

Example 2 An ultraviolet curable modified acrylate resin is sandwiched between a triacetate film having a thickness of 100 μI and a nickel standber having a concavo-convex signal, and a 7 to 10 kgf/
After pressing at a pressure of 1.5 cm", ultraviolet rays of about 20 hJ/c+s2 were irradiated through the surface of the triacetate film using a high-pressure mercury lamp, and then the film was peeled off from the stamper, and then the ultraviolet light source was used from the modified acrylate resin side. The film was irradiated with ultraviolet light at a light intensity of approximately 800mJ/C11' to obtain a film with the uneven signal transferred.Next, a 1,000-layer aluminum evaporated film was formed on the uneven surface of this film, and a hole was made in the center. The whole was cut concentrically with the center hole to obtain an optical disk for playback only.Since triacetate film has little birefringence, an aluminum hub 4 shown in Fig. 2 (8) and (B) was placed on this optical disk with concave and convex grooves. By pasting them together from the surface side using an anaerobic adhesive, a flexible optical disk having the hub structure shown in FIGS. 1(A) and 1(B) could be obtained.

After 1 mile, a 1.0 mm polymethacrylic plate was superimposed as a guide on the outer periphery of the hub portion of the flexible optical disk obtained in Example 1.2, so that it could be used for normal use as shown in Figure 3. A rigid optical disc was obtained.

That is, in FIG. 3, a hub 11 is mounted in the center of a flexible optical disk 10, and polymethacrylic plates 12 and 13 are layered on the upper and lower surfaces of the optical disk 10.

Effects of the invention: According to this invention, a flexible optical disc can be used without impairing its flexibility, and the principle of this invention of providing a hub structure on the flexible optical disc is as follows:
The present invention can be applied not only to optical discs that are disk-shaped, but also to optical cards that are rectangular.

[Brief explanation of the drawing]

FIG. 1 (Δ) is a plan view of a flexible optical disk of the present invention;
2(B) is a sectional view thereof, FIG. 2(A) is a plan view of the hub of the flexible optical disk of the present invention, FIG. 2(8) is a sectional view thereof, and FIG. 3 is the flexible optical disk of the present invention. It is a figure showing the structure of an example. 1.10... Flexible optical disk, 3.11... Hub, 2... Polymethacrylic plate, IO... Flexible optical disk, 12.13... Polymethacrylic plate. Applicant's agent Yuzo Yasugata! No./Figure 3

Claims (1)

[Claims] 1. A flexible optical disc having an optical recording layer provided on one side of a flexible film, characterized in that the central portion thereof has a hub structure.